1. Field of Invention
This invention generally relates to ligation type castration tools, and more particularly to a lever activated stretching tool for placing a continuous elastomeric band on animals for castration or removal of other body parts.
2. Background of the Invention
In animal husbandry, it becomes necessary at times to remove body parts and appendages. Examples of such actions include removing an animal's tail, testes, or other body parts. One way that this is done is to place a ligating band at the location where the body part is to be removed. The ligating band exerts sufficient tension upon the body part so as to restrict the flow of blood into and out of the body part. As a result of this restricted blood flow, the tissue within the appendage dies and after a period of time the appendage sloughs off.
Castration by ligation has become popular because of the simplicity of the process and the benefits it provides in avoiding undesirable consequences such as microbial infection, insect invasion, excessive bleeding, and the like. Ligation type castration of younger animals has been accomplished largely by use of small preformed continuous elastic or elastomeric bands, because of the economic viability provided by allowing rapid castration processing that can be accomplished by relatively unskilled persons.
The small elastic bands are generally placed by a spreading type tool having two arms interconnected in their medial portions to allow expansion of a band carried at one end portion of the tool against its elastic bias for placement over the scrotal pouch of the animal with subsequent release. This process works well with juvenile animals that do not have a mature testicular structure of larger size, but it has not been viable with larger animals having mature testicular structure such as bovine bulls, as a small preformed elastic band that would contract to a small enough configuration to provide ligation generally cannot be expanded sufficiently, either by its nature or by use of common spreading type tools, to allow passage over the larger testicular structure of the mature animal.
In addition, most devices for spreading the elastic ligation bands have not provided the user with the ability to sufficiently spread the elastic band so as to allow the passage of testes therethrough. Therefore, the use of elastic bands for ligation has been limited by the hand strength of the person utilizing the device.
Ligation castration with continuous preformed bands is easier and less complex than the formation of ligation banding in place. It has fewer possibilities for mistakes or errors. It provides a process that requires less care and skill on the part of an operator, and generally may be more easily accomplished by unskilled workmen without historical familiarity with the process. Elongate type ligation material that is formed in place also allows parameters for tensioning and band fastening by a clip that may be varied, either accidentally or deliberately by an operator, to provide results that are not necessarily uniform or consistent and may vary sufficiently to make the process inoperative or harmful to an animal.
Continuous band ligation material has more fixed parameters determined by the nature and configuration of the banding material itself, which are more independent of an operator's activities. The continuous banding material also is generally more durable than the elongate ligation material form in place, and is less expensive and more easily handled than the elongate material. There are therefore various advantages in using preformed continuous band type elastic material for ligation castrating, when the use of such material is possible.
The nature of the ligation castration process with small preformed continuous band elastic material defines the limits of the parameters required for the elastic bands usable for such purpose, and especially their relaxed size and elastic properties. Such bands must be small enough to fulfill their ligation purpose of providing sufficient elastic force or bias after placement and fastening about the neck of the scrotal pouch to cause atrophy of the tissue outwardly of the band while yet allowing sufficient expansion upon stretching to permit placement over the scrotal pouch.
Since a continuous ligation band must allow passage of the scrotal pouch and contain the testicular structure of an animal to be castrated through the orifice it defines and because of its small size, the bands must be enlarged by stretching to allow placement. The instant invention provides a tool to simply and easily accomplish the stretching of such bands of the required nature to a size and configuration that allows placement without damage to the elastic material. The present invention describes a system made up of a continuous elastomeric band that provides a desired amount of tensioning power together with a lever action band spreading tool that provides sufficient mechanical advantage to allow the bands in the present system to be sufficiently stretched so as to allow the bands to be placed over the appendages to be removed.
The lever action spreader of the present tool provides a secondary benefit by speeding the individual castration process and allowing a single operator to accomplish a greater number of castrations in a given period of time than could be accomplished with various prior tools. In the modem practice of animal husbandry, groups of several hundred animals may be castrated over a short period of time in a continuous operation. With prior tools not providing leveraging operation, the manual force required by a workman in operating various prior castration tools was often so great, and application of that force sufficiently difficult, that the process was tiring to a workman, particularly to his hand and wrist muscles, to such an extent that the workman's physical ability became a limiting factor in the number of sequential castrations that the workman could accomplish without substantial rest. This problem could be of such extent that it might cause permanent physical damage to a workman. The instant tool resolves this problem by requiring substantially less force, and is of such nature that it is not unusually tiring or damaging to a workman, allowing continuous operation over lengthy periods of time without adverse physiological effects that may cause injury or work slow down.
The present invention also provides an advantage in that it provides mechanical advantage for spreading an elastic band by providing that the spreading of the loop occurs when the pivoting handle is pulled toward a user. This enables the greatest amount of force to be placed upon the loop by the stronger muscles of the user and allowing the band to be held in a spread position by a person with one hand. This provides significant advantages in placing and maintaining the loop in an open position for placement upon a body party to be castrated.
An additional advantage of the present invention is that the closed position occurs when the lever bar of the device is past a generally perpendicular position. This configuration allows the rubber band to be stretched, and held in a stretched position with the physical forces of the band itself holding the loop open. This provides for increased advantages to the user as they may hold the device in one hand and use the other hand for other activities.
Additional objects, advantages, and novel features of the invention will be set forth in part in the description as follows, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.